A first-of-its kind senior living community is opening in Plymouth in July. But an activist says the development, Trillium Woods, lacks one thing: woods.

Former longtime Plymouth resident Steve Gardner says hundreds of trees, including 72 oak trees and a 42-inch-wide red oak that was an estimated 200 years old, were torn down. After 14 years of going through development plans to calculate tree losses in west metro suburbs, Gardner said this is his latest, and perhaps last, battle to save trees in Plymouth's northwest corner — the last section of the suburb to be newly developed.

"My last image of this was trees, a barn and a rolling hill," Gardner said, looking out at the $161 million development from an adjacent park. "That thing is huge. It upsets me that everything is vanishing."

Trillium Woods will have a 583,000-square-foot campus on 46 acres off Juneau Lane and County Road 47. With apartments and an assisted living center for more than 300 residents, a clubhouse, post office, bank and convenience store, it is what's called a continuing care retirement community. Residents live independently, yet have access to in-home health care services.

Nearby is the Willows, a housing development that Gardner also opposed because it removed 65 percent of the trees on the 28-acre site. At Trillium Woods, just over half of the 764 trees — 384 trees in all — were removed. The city counts trees that are 8 inches or wider.

Steve Juetten, city community development director, said Plymouth has to balance preserving trees with landowners' property rights, and 483 new trees were planted, along with 4,000 shrubs. "Trees have been cut, but they're replacing them with quality trees," he said of the developer, Life Care Services. "They went above and beyond."

A Trillium Woods spokeswoman said 24 of the 46 acres will be forest preserve and wetlands.

Plymouth has a less aggressive tree preservation ordinance than such neighboring communities as Maple Grove and Minnetonka, which follow an approach recommended by the Department of Natural Resources, preserving stands of trees rather than individual trees. Some cities protect certain species and ages of trees. But Plymouth's policy, written in 1985, calculates the number of tree inches on a site (not counting trees less than 8 inches wide) and allows developers to cut down half the combined tree inches; if they cut more than half, they have to replace trees.

"This always comes down to a balancing act, … saving trees but you also have to understand something has to happen out there," Juetten said. "[The developers] are doing a lot to make this as environmental as possible."

For years, Gardner has advocated for tree preservation at city meetings and used to host a cable-access TV show documenting trees being cut down in such cities as Golden Valley, Minnetonka and Maple Grove. The retired carpenter lived in Plymouth for 26 years before moving to ­Crystal. Now, he said, he's tired of failed fights at city halls.

"No one really got involved unless it was in their back yard," he said, carrying a folder of development proposals. "I just got discouraged."

By his calculations, 80,000 trees have been cut down in Plymouth in the past 15 years. For future projects, he said he urges the city to save more trees, especially older ones.

"I'm not going to be the person who chains themselves to a tree," he said. "I'm just trying to get them to save some trees for our beautiful community."

Staff writer Jim Buchta contributed to this report.